英文:
How to "left_join" multiple columns into one column within a single dataset?
问题
我有一个包含三列的数据框。我想要用另一列中的值来填充其中一个列中的缺失值，但我不想覆盖任何数据。我应该如何获得以下结果？
# 初始数据框:
DF$ST_1 <- c(100, NA, 100, 100, 200, 200, NA, NA, NA, NA, 200)
DF$ST_2 <- c(50, NA, 50, 50, 12, NA, NA, 50, 50, NA, 12)
DF$ST_3 <- c(5, NA, 5, 2, 3, 1, 1, 3, 4, 2, 11)
我想要的结果:
DF$ST <- c(100, NA, 100, 100, 200, 200, 1, 50, 50, 2, 200)
如您所见，我想保留ST_1中的所有值，当出现NA时，用ST_2中的值填充它。然后，我想保留所有这些合并后的值，并用ST_3中的值填充剩下的NA。在所有这些合并后，仍然会有一些剩下的NA。
英文:
I have a dataframe with three columns. I would like to populate the NAs that are in one column with values in another column, but I do not want to overwrite any data. How can I get the following results?
# Starting Dataframe:
DF$ST_1 <- c(100, NA, 100, 100, 200, 200, NA, NA, NA, NA, 200)
DF$ST_2 <- c(50, NA, 50, 50, 12, NA, NA, 50, 50, NA, 12)
DF$ST_3 <- c(5, NA, 5, 2, 3, 1, 1, 3, 4, 2, 11)
Results I want:
DF$ST <- c(100, NA, 100, 100, 200, 200, 1, 50, 50, 2, 200)
As you can see, I want to keep all the values in ST_1, and when there is an NA, fill it in with ST_2. Then, I want to keep all of the values from that merge, and fill in the remaining NAs with ST_3. There will still be some leftover NAs after all these merges.
答案1
得分: 1
library(dplyr)
DF %>%
mutate(ST=coalesce(ST_1,ST_2,ST_3))
ST_1 ST_2 ST_3 ST
1 100 50 5 100
2 NA NA NA NA
3 100 50 5 100
4 100 50 2 100
5 200 12 3 200
6 200 NA 1 200
7 NA NA 1 1
8 NA 50 3 50
9 NA 50 4 50
10 NA NA 2 2
11 200 12 11 200
英文:
library(dplyr)
DF %>%
mutate(ST=coalesce(ST_1,ST_2,ST_3))
ST_1 ST_2 ST_3 ST
1 100 50 5 100
2 NA NA NA NA
3 100 50 5 100
4 100 50 2 100
5 200 12 3 200
6 200 NA 1 200
7 NA NA 1 1
8 NA 50 3 50
9 NA 50 4 50
10 NA NA 2 2
11 200 12 11 200
答案2
得分: 0
你想要每行中的最大值吗？
基本 R 代码：
DF$ST <- apply(DF, 1, max, na.rm = TRUE)
英文:
So you're wanting the max value from each row?
base R:
DF$ST <- apply(DF,1,max,na.rm=TRUE)
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